A stray dog and a South Carolina animal shelter have become embroiled in a mystery after an aged black and white photo was found inside the animal’s collar.

CNN reports that animal control officers found a tan pit bull wandering the streets last December with a surprising secret. The canine had no microchip, or any identification of any kind, but when authorities checked his collar they found an ancient-looking photo of what appears to be a military man sitting on a railing and smiling into the camera.

The picture has baffled members of the Greenville County Animal Care staff, who have named their new charge “Soldier” after the subject of the photo. According to Susan Bufano, community relations coordinator for the shelter, no one has any idea who the pictured man is, or why it was placed on the dog.

“It’s so bizarre,” said Bufano. “Absolutely anything is possible.”

The details of Soldier’s collar make the stray’s story even stranger. The neck piece appears to be new, suggesting that the photo was added recently, and its design is different than most collars shelter workers have previously seen.

“It’s a really wide collar, canvas, and it’s got an opening,” Bufano told ABC News. “I can’t imagine this photo made it in there on accident.”

After Animal Care posted both a photo of the dog and mystery picture on their Facebook page, users raced to speculate on the nature of the shot. Many have suggested that Soldier may have belonged to homeless veteran who somehow lost possession of the animal.

While Soldier’s photo has gained widespread attention, the dog itself is in need of help. The 2-year old pit bull must soon be adopted, and may face euthanasia if an owner is not found. Animal Care states he is healthy and heartworm free.